234 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.
SWAMPS WITH MUDDY WATER.
Most Florida streams flow their whole length through sandy or rocky regions, and thus have no chance to become muddy. But the Apalachicola River, which has its sources among the red clay hills of Middle Georgia, is always muddy, and the Choctawhatchee and Escambia, which rise in the Eocene hills of southern Alabama, are quite muddy at times, especially in recent years since so much of the forest around their headwaters has been destroyed to make room for crops. The Ocklocknee and Suwannee have some clayey land in their drainage basins, and may become a little turbid at times, but the amount of mud carried by them in the course of the year is insignificant.
All muddy streams are subject to considerable fluctuation, and the vegetation along their banks is quite different from that which borders the more steady streams. Towards their mouths, however, the fluctuations become less and less, for it is obviously impossible for any river, no matter how swollen, to change the level of the ocean appreciably. Although we are at present unable to explain it, there is a marked difference between the vegetation of alluvial and that of estuarine swamps, even on the same stream.
ALLUVIAL SWAMPS.
(PLATE 19.I1)
The subjoined list of alluvial swamp plants is compiled from notes taken along the Apalachicola River in Jackson, Gadsden and Liberty Counties, within a few miles of River Junction and Aspalaga. (I have seen very little of the swamps of the Escambia and Choctawhatchee Rivers, but I have no doubt that in most respects they are intermediate between the Apalachicola and some of the smaller rivers which flow southward across Middle Florida, such as the Ocklocknee).
TREES

Taxodium distichum (cypress) Nyssa uniflora (tupelo gum)
(mostly in sloughs)
Salix nigra (willow) (mostly on
banks)
Planera aquahca Liquidambar Styraciflua (sweet
gum)
Quercus nigra (water oak) (mostly in slightly drier spots)
Quercus lyrata (swamp post oak) Platanus occidentalis (sycamore) Crataegus viridis (red haw)

Populus deltoides (cottonwood) Hicoria aquatica (swamp hickory) Gleditschia aquatica (locust) Carpinus Carolimiana (ironwood) Ulmus Americana? (elm) Celtis Mississippiensis? (hackberry)
Fraxinus Am e~icana? (ash) Acer saccharinvm (maple) (mostly on banks.)
Betula nigra (birch) (mostly on
banks)